1. Field of the Invention
This invention relates to a punch and ram assembly for punching workpieces and more specifically with guiding the punch and holding down the workpiece during the punching operation and also with stripping the punch from the workpiece after punching is completed.
2. Prior Art
Various types of punch press machines have in the past been provided with effective punch guiding and stripper arrangements to prevent damage or distortion to the workpieces. These devices have performed well when punching thin and moderate thicknesses of sheet metal. However, with the large presses capable of perforating heavy metal such as plate steel or the like, the stripping devices previously utilized are generally undesirable. With punching thicker metal plates the forces to withdraw the punches from the metal are large and in some instances may approach the downward punching forces. If sufficiently heavy stripper springs would be employed for use with plate stamping it would require excess space and also necessitate high forces to compress these heavy springs thereby adding greatly to the forces required in the punching operation. Further, when sheet metal is also to be worked on the same high compressive forces are required to compress these heavy stripper springs when only limited stripping forces are necessary.